I'm putting both Popes on my top 50 too:
Although Benedict XVI is said to be improving in health, I saw footage of his meeting with Francis where he stumbled - luckily there was a chair behind him.
As for Francis, he isn't very security conscious and has recently sacked his chief of security due to his strict and disciplinarian ways. I'd put him on as a wildcard, because, to be quite frank, he is asking for trouble.
A last Catholic possibility...you don't hear much from Cardinal Keith O' Brien these days...